Both HP BASIC and HTBasic do an implicit GRAPHICS INPUT IS assignment for you if you attempt to use graphic input statements before an explicit GRAPHICS INPUT IS. The difference is that HTBasic does the implicit GRAPHICS INPUT IS as soon as HTBasic is started, and HP BASIC waits until the first graphic input statement is executed. The only known effect of the different approaches is that under HP BASIC, a SYSTEM$("GRAPHICS INPUT IS") returns "0" until the first graphic statement is executed and HTBasic returns the correct value anytime.
